Preterm delivery is a major health problem in the United States and worldwide. Preterm delivery is often defined as delivery before 37 completed weeks of gestation and has been reported to be the major determinant of infant mortality in developed countries. Preterm delivery is more common in the United States than in many other developed countries, and is predominantly responsible for the relatively high rate of infant mortality in the United States as compared to many other developed countries. Over the past two decades, the rate of preterm delivery in the United States has been reported to have increased from 9% to 11%. In addition to preterm delivery, various other pregnancy-related conditions are major health problems in the United States and worldwide. These include, for example, the delivery of low birth weight neonates, delivery of small for gestational age neonates, pregnancy-related complications, fetal mortality, neonatal morbidity, neonatal mortality, infant morbidity, infant mortality, and childhood developmental delays.
Preterm delivery and other pregnancy-related conditions such as the delivery of low birth weight neonates and/or small for gestational age neonates have serious health, societal, and economic costs. For example, preterm delivery and the delivery of low birth weight neonates and/or small for gestational age neonates can lead to neonatal morbidity, longer stays in the neonatal intensive care unit, and a higher risk of long term morbidities including, for example, cerebral palsy, mental retardation, and learning disabilities.
A number of risk factors for preterm delivery and other pregnancy-related conditions (e.g., previous pregnancy resulting in preterm delivery, previous delivery of low birth weight and/or small for gestational age neonates) have been identified. For example, women who have had a previous spontaneous preterm delivery are at high risk for preterm delivery in subsequent pregnancies. Other risk factors for preterm delivery include: tobacco use during pregnancy (e.g., smoking); infection; multiple gestations (twins, triplets, etc.); alcohol use, abuse, or dependence during pregnancy; substance use, abuse, or dependence during pregnancy; poor nutrition during pregnancy; stress, anxiety, and/or depression; insufficient weight gain during pregnancy; advanced maternal age; African-American descent; and low socio-economic status. Tobacco use or exposure, in particular smoking, during pregnancy is a significant risk factor for preterm delivery and other undesirable maternal, fetal, and neonatal outcomes.
Intramuscular injection of steroids such as 17-alpha-hydroxyprogesterone caproate (“17-HPC” or “HPC”) in the gluteus maximus have been used to reduce the risk of preterm birth, but such injections can be painful, and/or may cause the buildup of scar tissue especially since the injection must be repeated weekly for up to 21 weeks. Further, intramuscular injections involve the risk of nerve injury, especially the risk of sciatic nerve injury from dorsogluteal intramuscular injections. There is a need for an alternative route of administration that may, for example, minimize pain and increase the likelihood of patient compliance.